The SecurityCallbackModule is a user written module that can receive
events from the mod_security Erlang Webserver API module.
This module only exports the function(s),
event/4,5,
which are described below.

event/4 or event/4 is called whenever an event
occurs in the mod_security Erlang Webserver API module (event/4 is
called if Address is undefined and event/5 otherwise).
The What argument specifies the type of event that has
occurred, and should be one of the following reasons;
auth_fail (a failed user authentication),
user_block (a user is being blocked from access) or
user_unblock (a user is being removed from the block list).

Note

Note that the user_unblock event is not triggered when
a user is removed from the block list explicitly using the
unblock_user function.